GU4

The GU4 is a 2-pin cap with a 4mm gap between pin centres, and a pin diameter of around 1mm. The glass base of the GU4 has a grip channel cut into one or both sides. This cap is used on low-voltage MR11 and MR8 reflector lamps, which are small spotlights used in applications such as track lighting, display cases, and decorational lighting.